Facebook, Apple, Google, Microsoft, Yahoo ! and AOL asked lawmakers to restrain the National Security Agency, saying they want to "counter erroneous reports" that they give intelligence agencies direct access to their servers.

"Our companies believe that government surveillance practices should also be reformed to include substantial enhancements to privacy protections and appropriate oversight and accountability mechanisms for those programs," the companies wrote yesterday to Senator Patrick Leahy, a Vermont Democrat who leads the Senate Judiciary Committee, and three other lawmakers.

The companies also want permission to publish statistics about how often they turn over customer data in response to legal orders by the U.S. government.

The NSA is under scrutiny in Congress and abroad in response to revelations that it has spied on foreign leaders, broke into networks and gathered the e-mails and bulk phone records of innocent Americans. Most of the revelations were exposed by former NSA contractor Edward Snowden.

"The volume and complexity of the information that has been disclosed in recent months has created significant confusion here and around the world, making it more difficult to identify appropriate policy prescriptions," the companies said in the letter.

The companies hope that by being transparent about their interactions with the government they will be able to correct impressions that they give the NSA access to their servers or help the agency collect bulk Internet records.

Earlier this week the Washington Post reported that NSA has tapped fiber-optic cables overseas in order to gather data from Google and Yahoo.

"U.S. service provider communications make use of the same information super highways as a variety of other commercial service providers," the NSA said. "NSA must understand and take that into account in order to eliminate information that is not related to foreign intelligence."